Existing code is broken to still cover the hardware problem.
Basically, in Martell, you were supposed to do orbit shots to complete it, and if you fired them off, you could finish the mode quickly. Unfortunately, Stern screwed up and placed the diverter assembly for Prem/LE *just slightly* wrong, so left orbit shots often to usually rattled around and failed to complete, dropping into the pops or back down to the left. A fix was supposed to be coming for MONTHS. When Stern finally released "the fix" it was adding an option to just disable the feature in software and then saying the game worked "as designed" with the orbit feature of Martell disabled. It was 100% total and complete BS and a slap in the face to Steve Ritchie's design, but he had to eat it and keep his mouth shut in public about it. At the time there was a slo-mo video showing the ball not finishing the orbit right and rattling into the rollover lanes instead of going all the way around. I'll see if I can find the link.
EDIT: Found it.
You can see that the angle of the diverter is off just a small amount, and so the ball doesn't follow it around and transition to the ball guide on the other side, but instead hits the other side and that causes it to rocochet onto the lane guides on the other side.